Method of controlling a plow of a paving machine

ABSTRACT

A method of controlling a plow of a paving machine includes receiving a transmission signal indicative of a transmission status of the paving machine by a first sensor. The method includes receiving a screed mode signal indicative of a mode of operation of a screed of the paving machine by a second sensor. Further, the method includes receiving a parking brake signal indicative of a status of a parking brake of the paving machine by a third sensor. A position of the plow is controlled by a controller based on the transmission signal, the screed signal and the parking brake signal.

TECHNICAL FIELD

The present disclosure relates generally to a paving machine. More specifically, the present disclosure relates to controlling a plow coupled with the paving machine.

BACKGROUND

Paving machines typically include a tractor with a hopper for receiving paving material. The hopper is located at the front of the paving machine. A feeder conveyor for delivering the paving material to a spreader auger is located to the rear of the paving machine. The auger distributes the paving material laterally behind the tractor to the road surface in front of a screed assembly. The screed assembly is drawn behind the paving machine by a pair of pivotally mounted tow arms. The screed smoothens out and compresses the paving material. The paving machine may be driven on wheels or may include a track assembly. The paving machine may further include a plow. The plow is an apparatus that aids in removing material such as obstacles and dirt etc. from in front of the wheels or tracks of the paving machine. Generally, the plow is mounted on the back side of a front bumper of the paving machine.

The plow has two operating configurations: a working configuration and a storage configuration. Typically, the plow is raised and lowered manually by an operator to toggle between the two configurations. Sometimes, this may lead to unintentional damage to the plow if the operator forgets to put the plow in the storage configuration after paving operation is completed. Mat defects may be introduced in the road surface during paving in case the plow is not lowered in to the working condition during paving. Further, the operator manually adjusting the plow may not be clearly visible from an operator station and may lead to safety concerns.

U.S. Pat. No. 7,033,105 discloses a road paving equipment having a tire track remover. The road paving equipment is provided with a pair of blade assemblies, each including a semi-flexible blade with a lower edge and an upper edge. The blade assembly is attached to the surface of a road paving vehicle near and behind the rear wheels of the vehicle in such a manner that the lower edge of the blade is in contact with the road surface. The blade assembly also includes means for vertical adjustment of blade while in use. The blade assembly levels the tire tracks created by the wheels of the road paving equipment on the road surface by vertically adjusting the blade assembly.

Thus, there is a need for a method to control the plow of the paving machine without manual interventions.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, a method to control a plow of a paving machine is provided. The method receives a transmission signal indicative of a transmission status of the paving machine through a first sensor. The method receives a screed mode signal indicative of a mode of operation of a screed of the paving machine through a second sensor. The method further includes receiving a parking brake signal indicative of a parking brake status of the paving machine through a third sensor. Thereafter, the method includes controlling a position of the plow through a controller based on the transmission signal, the screed signal and the parking brake signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a paving machine having a plow, in accordance with one embodiment of the present disclosure;

FIG. 2 is a perspective view of the plow of the paving machine of FIG. 1, in accordance with one embodiment of the present disclosure;

FIG. 3 is a block diagram of a control logic of actuating the plow on the basis of operational parameters of the paving machine, in accordance with one embodiment of the present disclosure; and

FIG. 4 is a flow chart illustrating a method of controlling the plow, in accordance with one embodiment of the present disclosure.

DETAILED DESCRIPTION

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts. Referring to FIG. 1, an exemplary paving machine (hereinafter referred to as “the machine”) is illustrated. The machine 10 includes a tractor 12 having a frame 14 with a set of ground engaging members 16 coupled with the frame 14. Though the ground engaging members are illustrated as wheels in FIG. 1, in various alternative embodiments, the ground engaging members may be tracks. The ground engaging members may include a set of front wheels 15 and a set of rear wheels 16. The ground engaging members are driven by an engine 18 via a transmission (not shown). The transmission may be a hydrostatic transmission or a mechanical transmission. The machine 10 may also include a parking brake (not shown).

A screed assembly 20 is coupled to the tractor 12 and attached at a rear end of the machine 10 to spread and compact paving material into a layer or mat of desired thickness, size and uniformity on a ground surface. In the illustrated embodiment, the ground surface is abase surface on which a paving operation is performed. However, the ground surface may alternatively be a finished or an unfinished ground on which the machine 10 manoeuvres or travels without performing a paving operation. The machine 10 also includes an operator station 22 having a seat and a console, which may include various controls for directing operations of the machine 10. The screed assembly 20 may also include an operator console 24.

The machine 10 further includes a hopper (not shown) configured to store a paving material, and a conveyor system (not shown) including one or more conveyors configured to move the paving material from the hopper to the rear end of the frame 14. The machine 10 further includes an auger (not shown) coupled to the tractor 12 and located between the tractor 12 and the screed assembly 20. Specifically, the auger is placed at the rear end of the frame 14 and adjacent to the screed assembly 20. The auger is configured to receive the paving material supplied by the conveyors and spread the paving material evenly ahead of the screed assembly 20.

The machine 10 further includes plows 26 to remove any material such as obstacles, dirt etc. from in front of the set of front wheels 15. The plows 26 are attached to a front bumper 28 of the machine 10. Specifically, the plows 26 are attached to a back side of the front bumper 28. Although only one plow 26 is visible in the side view of the machine 10 shown in FIG. 1, a similar plow 26 is attached in front of the other front wheel 15 which is not visible.

Referring to FIG. 2, the plow 26 includes a plate 30 and a scraper 32 attached to the plate 30. The plate 30 may be rigid, and preferably fabricated from a metal. Any other material which suits the need of the application may also be used to fabricate the plate 30. The scraper 32 may be fabricated from a hard plastic material or any other such material which suits the need of the application. The plate 30 has a first surface 36 and a second surface 38. The scraper 32 is attached to the plate 30 on the first surface 36 using a fastening plate 42 and any known mechanical fastening means 34, such as, nut and bolts. Specifically, the plate 30 includes multiple apertures (not shown) located at same horizontal level to receive the mechanical fastening means 34 therethrough, and the scraper 32 includes longitudinal slots 40. After adjusting a height of the scraper 32 with respect to the ground surface, so that it either engages the ground surface or remains at a predefined distance from the ground surface, the fastening plate 42 is placed transversely over the longitudinal slots 40 so that a number of apertures 44 in the fastening plate 42 corresponds to the multiple apertures in the plate 30. The mechanical fastening means 34 then couples the scraper 32 with the plate 30 through the fastening plate 42. Since, the scraper 32 may wear at bottom and lose contact from the ground surface, the height of the scraper 32 can be re-adjusted through the longitudinal slots 40 to regain contact with the ground surface.

As shown in FIG. 2, a bracket 46 is attached to the second surface 38 of the plate 30. The bracket 46 may be attached to the plate 30 by any mechanical fastening means. Alternatively, the bracket 46 may be attached to the plate 30 by welding, soldering or any other similar process. Further, an arm 48 is attached to the bracket 46 to couple the plow 26 with a hydraulic actuator 62 (shown in FIG. 3), such as, a double acting hydraulic cylinder.

A control system 50 for controlling the plow 26 is shown in FIG. 3. The control system 50 includes a controller 52. The controller 52 may be a single controller, or alternatively may include more than one controller controlling different functions and/or features of the machine 10. The controller 52 may be an Electronic Control Module (ECM) of the machine 10. The controller 52 is in communication with various sensors associated with the machine 10. The controller 52 receives signals from various sensors including at least a first sensor 54, a second sensor 56 and a third sensor 58.

The first sensor 54 provides a signal indicative of a status of the transmission of the machine 10. The status of the transmission may indicate a selected gear in a gearbox of the transmission. The first sensor 54 may detect a selected forward or reverse gear in the gearbox. The first sensor 54 may be a magnetic pick-up device that detects the movement of a gear tooth in the gearbox. The first sensor 54 generates signals indicative of the status of the transmission. The controller 52 receives signals from the first sensor 54 and determines the status of the transmission of the machine 10.

The second sensor 56 provides a signal indicative of a mode of operation of the screed assembly 20. The screed assembly 20 slides over the paving material to provide a uniform thickness. This mode of operation of the screed assembly 20 may be called as a float mode. The second sensor 56 determines whether the screed assembly 20 is operating in a float mode. The second sensor 56 may detect a distance between the screed assembly 20 and the ground surface to indicate the mode of operation of the screed assembly 20. The second sensor 56 may be any type of sensor that may detect distance between the screed assembly 20 and the ground surface. Accordingly, the controller 52 receives signals from the second sensor 56 and determines the mode of operation of the screed assembly 20. In another embodiment, the second sensor 56 may provide the controller 52 with a signal indicative of a distance between the screed assembly 20 and the ground surface. The controller 52 may have pre-stored information or look up tables to determine the mode of operation of the screed assembly 20 based on the signal provided by the second sensor 56.

The third sensor 58 provides a signal indicative of a status of the parking brake. The third sensor 58 may detect whether the parking brake is activated. The parking brake system may utilize a mechanical, hydraulic or electronic means to activate or deactivate the parking brake on the machine 10. The third sensor 58 may detect parameters such as a mechanical displacement, a hydraulic fluid pressure or an electric current etc. to determine whether the parking brake is activated. Accordingly, the controller 52 receives signals from the third sensor 58 and determines the status of the parking brake.

The controller 52 may also receive additional signals indicating operational parameters of the machine 10. The operational parameters may include a speed of the machine 10, an operating mode of the machine 10 such as a paving mode or a travelling mode. In an embodiment, the operator station 22 includes a function switch therein. The function switch is turned ON to start a paving operation. The controller 52 checks whether the function switch is ON to detect the operating mode of the machine 10. Based on the signals received, the controller 52 determines if the machine 10 is in the paving mode. If the machine 10 is in the paving mode, the controller 52 controls the position of the plow 26 on the basis of the signals received from the first sensor 54, the second sensor 56 and the third sensor 58. The controller 52 determines whether the transmission signal provided by the first sensor 54 indicates the selection of a gear. The controller 52 determines whether the signal provided by the second sensor 56 indicates the mode of operation of the screed assembly 20 as the float mode. The controller 52 further determines whether the signal provided by the third sensor 58 indicates the status of the parking brake as deactivated. If the signals provided by the first sensor 54, the second sensor 56 and the third sensor 58 meet the required conditions, the controller 52 moves the plow 26 to the engaged position. In case, any of the conditions are not met, the controller 52 moves the plow 26 to the stowage position.

The controller 52 controls the position of the plow 26 through a control valve 60. The control valve 60 may be a check valve. The control valve 60 controls a supply of hydraulic fluid to the hydraulic actuator 62. The hydraulic actuator 62 may be a dual acting hydraulic cylinder. A dual acting hydraulic cylinder includes a piston rod and ahead movable inside a cylindrical body. The cylindrical body may have a first end and a second end. The cylindrical body has openings for supplying hydraulic fluid on the first and the second end. The piston head is moved in the cylindrical body between the first end and the second end based on the supply of hydraulic fluid from either end. The two positions of the piston head on the two ends of the cylindrical body may correspond to an engaged position and a stowage position of the plow 26. Depending upon the signals received from the first sensor 54, the second sensor 56 and the third sensor 58, the controller 52 determines the position of the plow 26. Thereafter, the controller 52 controls the control valve 60 to supply hydraulic fluid to the hydraulic actuator 62. The hydraulic actuator 62 actuates the arm 48 of the plow 26 to set the plow 26 in either of the engaged position or the stowage position.

Although the control of the plow 26 is explained by example of the dual acting hydraulic cylinder as the hydraulic actuator 62, it should be understood that any other similar means to actuate the arm 48 of the plow 26 may be used without departing from the scope of the present disclosure.

INDUSTRIAL APPLICABILITY

Paving machines are used to lay a paving material on a ground surface. It is important to maintain a constant elevation of the ground surface being paved. This ensures quality of the finished surface. The plows 26 are provided in front of the ground engaging members 16 to clear any material in front of the ground engaging members 16 that may adversely impact the paving operation. However, currently the plow 26 has to be manually actuated between the engaged position and the stowage position. The present disclosure provides a method 64 of controlling the plow 26 based on the operating conditions of the machine 10. The method 64 ensures that the plow 26 always remains in correct position for any operating condition of the machine 10 and avoid any physical damage to the bracket 46 of the plow 26. Also, it helps in increasing the productivity of the paving operation by saving time incurred in manually actuating the plow 26. Further, safety of the operator is also ensured which may otherwise be at risk while manually actuating the plow 26.

The method 64 is explained with the help of a flowchart as shown in FIG. 4. The method 64 at step 66 receives the signal indicating the status of the transmission from the first sensor 54. The controller 52 determines whether the gear is engaged in the forward or the reverse direction. The method 64 at step 68 receives the signal indicating the mode of operation of the screed assembly 20 from the second sensor 56. The controller 52 determines whether the screed assembly 20 is operating in the float mode. The method 64 at step 70 receives the status of the parking brake by the third sensor 58. The controller 52 determines whether the parking brake is deactivated.

The method 64 at step 72 controls the position of the plow 26 by the controller 52 based upon the signals provided by the first sensor 54, the second sensor 56 and the third sensor 58. The controller 52 determines the position of the plow 26 as the engaged position if the first sensor 54 indicates the status of the transmission as the gear selected in a forward direction, the second sensor 56 indicates the mode of operation of the screed assembly 20 as the float mode and the third sensor 58 indicates the status of the parking brake as deactivated. The controller 52 determines the position of the plow 26 as the stowed position if any of the above mentioned conditions are not met. The controller 52 controls the control valve 60 to supply hydraulic fluid to the hydraulic actuator 62. The hydraulic actuator 62 may be the dual acting hydraulic cylinder or any other similar means. The hydraulic actuator 62 actuates the arm 48 of the plow 26 to set the plow 26 in either of the engaged position or the stowage position.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof. 

What is claimed is:
 1. A method of controlling a plow of a paving machine, the method comprising: receiving a transmission signal, through a first sensor, indicative of a transmission status of the paving machine; receiving a screed mode signal, though a second sensor, indicative of a mode of operation of a screed of the paving machine; receiving a parking brake signal, through a third sensor, indicative of a status of a parking brake of the paving machine; and controlling a position of the plow, through a controller, based at least on the transmission signal, the screed mode signal and the parking brake signal.
 2. The method of claim 1, wherein the position of the plow is controlled using a dual acting hydraulic cylinder and a control valve. 